In recent years a number of industries have adopted the FIBC or bag-in-box concept for storing and transporting liquid and particulate commodities in relatively large quantities. For example, the FIBC or bag-in-box concept has been employed for transporting in bulk such diverse products as vegetable oils, salad dressings, syrups, soy sauce, peanut butter, pharmaceuticals, talc, motor oil, industrial chemicals, detergents in liquid or powder form, and toiletry products or ingredients.
The FIBC concept is a bulk container system comprising a flexible liner in a flexible or semi-flexible bag. In one embodiment, a FIBC bag is made of a woven material (e.g., woven polymer, TYVEX®, canvas, wire mesh or net). The flexible liner is typically chemically resistant and impermeable to water and air and serves as the container for a selected commodity. The FIBC bag serves as a protective container for the liner and its contents. A FIBC bag is disclosed in U.S. Pat. No. 4,596,040 to LaFleur et al., which issued Jun. 17, 1986, and is hereby incorporated by reference in its entirety.
The bag-in-box concept comprises a flexible liner and a rigid or semi-rigid box. The flexible liner is typically chemically resistant and impermeable to water and air and serves as the container for a selected commodity. The box may be made of plywood or other wood materials, cardboard, fiberboard, metal, or plastic. The box serves as a protective container for the liner and its contents. A box for a bag-in-box system is disclosed in U.S. Pat. No. 6,533,122 to Plunkett, which issued Mar. 18, 2003, and is hereby incorporated by reference in its entirety. A bag for use in a bag-in-box system is disclosed in U.S. patent application Ser. No. 10/818,882, which was filed Apr. 6, 2004, is entitled “Bag With Flap For Bag-In-Box Container Systems” and is hereby incorporated by reference in its entirety.
By way of example, a liner used for shipping commodities in bulk, via a FIBC or bag-in-box system, typically may have a volume on the order of 300 gallons. In one embodiment, the liner will include at least a drain fitting near the bottom of the liner whereby the liner's contents may be removed. In other embodiments, the liner will include at least a filler fitting near the top of the liner whereby the liner may be filled with its contents. In other embodiments, the liner will include both a filler fitting near the top of the liner and a drain fitting near the bottom of the liner. In one embodiment, the drain fitting is on the gusseted side as described with respect to U.S. Patent Application No. 60/720,855, which was filed Sep. 26, 2005, entitled “Flexible Liner With Fitting On Gusseted Side.”
The liner may be of any suitable configuration. For example, the liner may be generally shaped like a cube, or a pillow, a parallelepiped, or any other suitable configuration. It also can be configured so that a cross-section that is generally parallel to the top and bottom of the liner is square, rectangular, circular, or any other suitable geometry.
In embodiments of the liner with at least a drain fitting, the outer container (i.e., the bag of a FIBC system or the box of a bag-in-box system) is provided with a discharge opening at or towards the bottom end of the outer container through which the liquid or particulate contents can be discharged from the liner via its drain fitting. The discharge opening of the outer container may be fitted with a drain fitting that mates with or accommodates the drain fitting of the liner. This mating arrangement between drain fittings of the liner and outer container assures that material discharged from the liner will be directed to the intended receiving facility and prevents the material from accumulating in the bottom of the outer container.
In embodiments of the liner with at least a filler fitting, the outer container usually comprises a cover or top panel that is removable to permit access to the liner and the filler fitting.
One consideration of the FIBC or bag-in-box mode of shipment of materials in bulk is that the outer container can be a non-returnable or one-way container. For example, where the outer container is a box for a bag-in-box system and is generally made of a corrugated fiberboard or the like, the box can be discarded after use. Alternatively, the box may consist of interlocking panels of metal, wood, or a stiff or rigid plastic material, in which case the box may be disassembled and returned to the shipper after the associated liner has been emptied of its contents.
Where the outer container is a bag for a FIBC system and is made of a low cost woven material, the bag can be discarded after use. Alternatively, where the material of the bag is more expensive, the bag may be collapsed and returned to the shipper after the associated liner has been emptied of its contents.
With respect to the FIBC and bag-in-box concepts as applied to bulk shipment of commodities, the plastic flexible liners have taken various forms. One common form is the so-called “pillow” type, which consists of at least two sheets of plastic film sealed together at their edges. Another common form is the six-sided flexible liners (e.g., liners that take the shape of a cube or rectangular parallelepiped when filled) made from a plurality of sheets of plastic film. An example of this is described with respect to U.S. patent application Ser. No. 10/900,068, which was filed Jul. 27, 2004, entitled “Flexible Liner For FIBC Or Bag-In-Box Container Systems,” hereby incorporated by reference in its entirety.
Regardless of the form the liner takes, the top half of the liner is generally more susceptible to flex crack failure than the bottom half from the film moving back and forth, typically resulting from greater product movement toward the top of the product than toward the bottom. This can lead to a breakdown of the liner's structural and/or barrier properties, possibly resulting in product degradation, loss of shelf life, contamination, damage to the contents, and/or loss of materials. In the past, particularly with pillow-shaped liners, this flex cracking has been reduced by packing the top part of the bag or box, above the liner, with a dunnage material to immobilize the upper portion of the liner. Having to add dunnage materials increases the cost and time required to ship goods and materials and does not always work, as some materials tend to settle over time, and liners are not necessarily always filled to the same height or extent.
There is a need in the art for a system and method of reducing flex crack failure in the liner of a FIBC or bag-in-box system, thereby preventing breakdown of the liner's structural and/or barrier properties and the harms associated with such breakdowns.